Telephone system with party lines



Feb. 6, 1951 H. L. LESIGNE 2,540,896

TELEPHONE SYSTEM WITH PARTY LINES Filed April 6, 1946 3 Sheets-Sheet 2Near/E450 Fl GU RE 2 MUU'lPllD llvwwrale fiewm tons team/v:

Feb. 6, 1951 1 s1 N 2,540,896

TELEPHONE SYSTEM WITH PARTY LINES Filed .April 6, 1946 3 Sheets-Sheet 3FIGURE 3 nboooome HENRI tows lea/6N6 Patented Feb. 6, 1951 TELEPHONE.SYSTEM WITH PARTY LINES Henri Louis- Lesigne, Vanves, France,assigno'rto Compagnie Generale dElectricite, Paris,

France, a French' corporation Application April 6, 1946, Serial N 0.660,080 In France July 1, 1942 EClaims. 1

This invention relates in general to telephone systems using partylines.

In known systems, the connected subscribers on a party line before usingthe line should ascertain Whether the line is free or busy, by either avisible signal or an audible signal. Certain systems utilize for theoperation of the switching members an individual battery at eachsubscriber s station.

The present invention is characterized by the registration of a call'either by the operation of a relay having mechanical engagement actuatedbythe'subscribers magneto or by a control member controlled manuallywith mechanical engagement, such asa manual change over switch ormanually operated key.

The present invention permits getting rid of these inconveniences, thatis to say, that each subscriber's station on a party line, initiates hiscall without preliminary checking up, and awaits his connection, while,for the purpose of economy and surety, the operation of the station nolonger requires an individual battery at each station.

The present invention is further characterized bya circuit arrangementwhich permits the operation of an individual selector for each station,the-stopping of this selector on the calling station, and the calling ofthe calling station, and also the establishment of communication withanother subscribers station ontheparty line, withoututilizing a looalvoltagesource, as a battery.

The present: invention is also characterized by anarrangementand'connection of the operating elementssuchthat the,particular pieces-or equipment: at each subscribers station areinterchangeable and without it being necessary to effect any mechanicalmodification. of the parts or a change in their connections- Otherfeaturesv will appear from. the following description and; theaccompanying drawings, wherein:

Fig. I shows the equipment of'each. subscribers stationonthe party.line;

Fig. 2. shows the; equipment ofsthe party lines connected to a manualexchange orpanel at: the

central ofilce;

Fig. 3 showsthe equipment of, the party lines connected to a: rural;automatic exchange; and

Fig. 4 shows a modification of Fig. 1,,for the equipment of eachsubscribers station in the case in which the" call asrmade is registeredby the engagement of an operating.- member controlled manually.

Considerfirstthe case of. a localcall. utilizing the equipment connectedtoa manual-exchange, as shown in Fig. 2.

The subscriber who desires to make a call rings his magneto, whichcauses excitation of relay 2 at the subscribers station (Fig. 1') overthe circuit: the contact of the magneto, bottom contact of the switchhook; winding of rel'ay'2,

contact RZi, (lower contact of-relay 2 bot tom contact of switch hook,magneto:

Relay 2 having a mechanical lock, remains closed If thecallingsubscriber takes ofihis receiver,

he hears the sound producedby-a buzzer at the subscribers station fromwhich the short cir-- cuit is removed by contact R21, of relay 2' (Figs;1 and 4) The energization of relay 2' into operatedposi tion producesthe call to the manualexc'hange over the circuit: ground, rectifierl-Stll in the direction of passage of current, contact T23- of relay 2-,rest contact of'sector a of theindividual selector, party line wireB(Fig. 2), contact C'o; upper winding of relay 32', positivebatteryterminal.

Relay 32 is held closed over the circuit, ground,

lower winding ofrela'y 32, contact T321 of relay 32, resistance,negative battery terminal.

The calling lamp is lighted overthe circuit-2 ground through the pilotrelay, contactT325- of. relay 32, contact R2 23of relay 22; callinglamp, negative battery terminal.

The combiner rotary switch X3- rotates to reach its position i by actionof the circuit? ground, contact T323 of relay 3 2, contact xteo;

contact X3, actuating winding ofrotary switch X3, negative batteryterminal.

X360 is the zero position or contact stud of the contact orbank e ofthecombiner X3. This combiner "XS-is an auxiliary rotary switchwhichusually has eleven positionsnumbered from zero to ten inclusive,and its function is to complete various different combinations ofcontacts and The comin eleven vertical columns numbered from-zero toten, starting from the left, so that am is-the farthest right contact inthe upperright corner of. Fig. 2. These contacts are shown in thedrawings as small cross-hatched squares.

The circuit of the lamp indicatingthatwthe line is free is interrupted.at contact an.

Relay'29 isenergizediover-the circuit: grounds contact T323 of relay 32,rest contacts of? bank Kid, contact R262 of relay 26, actuating windingof relay 29, resistance, negative battery terminal. Xid is the bank d ofrotary switch Xi.

- The four banks a, b, c, d of rotary switch Xi are shown adjacent itsmagnet.

Rotary switch X l is energized over the criouit through contact T294 ofrelay 29.

The negative battery terminal is connected to the party line wire A overthe circuit; negative battery terminal, resistance, rest contact ofbani; Xia, contact 12% of relay 29, wire A (Fig. l), rectifier 592 inthe direction of passage of current, Winding l or rotary switch sectorb, rest contacts of rotary switch sector b, ground. Winding i is thenenergized.

Fig. 4 shows the modifications in the circuit of the subscribers stationof Fig. 1 when employing a member with mechanical engagement controlledmanually, such as a change-over switch or manually operated key, whichomits a relay.

The party line extends from the terminals A, B,. onthe right of Fig. 1or Fig.2, to the terminals A, B, at the central office shown in Fig. 2.

' The wires i, 2, 2 at the top of Fig. 2, lead to the operators dialkey, including its contacts and dial lamp.

In the upper right corner of Fig. 2, to the right of contact 222, thethree lamps shown are, from top to bottom, the unoccupied lamp, the,supervision lamp, and the calling lamp.

, Then relay 28 is energized over the circuit: (Fig. 2) contact T222 ofrelay 22, and at contact T22l of relay 28 short circuits the winding ofrelay 2?? which opens, rotary switch Xi then advances one step, theimpulse on the party line wire A is terminated, which causes all theindividual selectors'to advance one step.

Relay 22 is again energized over the circuit through ground provided bybank Xld.

-Throu gh the circuit: contact T22i, contact T2 22a positive batteryconnection, and a ground, are connected respectively, to the wires B andA upon each'impulse, which causes all the individual selectors toadvance, the windings I (Fig. 1) being then looped on the line.

The calling unit has then been set into operation over the circuit:ground, contact al, and the waiting signal is sent by contact T326 ofrelay 32.

Ihe calling machine connections are shown by five arrows in the lowerright corner of Fig. 2, and these connections are multipled. The callingmachine is put into circuit over: ground, contact a, line M, and thewaiting signal is sent by line 22, condenser, T326.

When the selector of the calling subscribers station reaches the azimuthcorresponding to the number of the subscribers station, the relay 26(Fig. 2) is held over the circuit: (Fig. 1) ground, rectifier 5223 inthe direction of passage of cur-- rent, resistance 59%, contact T22 ofrelay 2, contacts of the sector a, line wire B (Fig. 2), contact 322i ofrelay 29, contact fi, contact R252 of relay 2%, upper winding of relay22, positive battery terminal.

At contact T265, relay 26 is held and at contact R252 opens theactuating circuit of relays 22 and 22.

-Through contact T266 of relay 22 and the contact dl, the relay 2% isenergized and is then held by contact T222 of relay 24.

The relays 2 ands of the equipment of the called subscriber areenergized over the circuit: negative battery terminal, resistance (Fig.2) contact T223 of relay 26, contact fl, contact 4 R29! of relay 22,wire B (Fig. 1), contact of sector a, contact R23, windings of relays 2'and 3' in series, rectifier i906, ground.

Through contacts T2l, T22 (Fig. 1) the connection of the subscribersstation to the line wires is completed over the circuit: through contactT3i', the relay 3' holds relays 2 and 3'; through contact T33, thecondenser of the wire A is short circuited, relay 2' has brought relay 2to rest by a locking mechanical device, and is held, being mechanicallyengaged and locked.

If the subscriber has taken ofi his receiver, he then hears the waitingsignal.

When the operator plugs in, relay 22 (Fig. 2) isenergized over thecircuit: ground, auxiliary contact of the jack, contact T22! of relay22, winding of relay 22, negative battery terminal. At its contact T222,relay 22 is held, and at its contact R223 opens the circuit of thecalling lamp, rotary switch combiner X3 rotates to reach its position 2by action of the circuit: ground, contact T22| of relay 22, contact T248of relay 22, contact T254' of relay 2%, contact cl, contact of combinerXS, actuating winding of combiner X3, negative battery terminal.

The actuating winding of relay 32 (Fig. 2) is short circuited by contact012 of the combiner and opens. The relays 2 and 3' (Fig. 1') are heldover the circuit: negative battery terminal, resistance, contact 02,line wire B. 1

At the subscribers station (Fig. 1), the rectifier placed between groundand T22 permits the pasj age of the current, when on the rest positionof the individual selector, the wire B is connected to a relay tied topositive battery (case of the calling of a subscribers station) At theend of the communication, negative battery is placed on wire B, in therest position of the selector. The preceding rectifier opposes itself tothe passage of the current, the relay 3 is energized through therectifier connected tothe midpoint of the relays 3 and 3. a

The rectifier placed between ground and T22 permits the passage of thecurrent at the time of the rotation of the selector, the wire B beingconnected to a relay tied to positive battery. This relay becomesenergized when the selector finds itself on the position of a stationbeing called. 7 r e The rectifier connected to the midpoint of therelays 3 and 3, being in the'inverse sense,'is opposed to the current inthe position of circuit;

ground, rectifier, relay 3', relay 2', R23.

When the negative battery is placed on the line wire B, the role of thetwo preceding rectifiers is changed. The first rectifier opposes thepassage of current, the second rectifier permits relays 2 and 2 tobecome energized. I

During the advance of the individual selector, the relay I is energizedby apositive battery impulse on line wire B, the return being effectedthrough the rectifier in the sense of passing of current, the Wire A andground. The relays 2' and 3' cannot become energized, the rectifierconnected to the midpoint of the relays 3 and 3 being then opposed tothe passage of current.

At the time of energization of the relays 2 and 3' by a negative batteryimpulse on the wire B, the relay 1 remains at rest, the rectifier inseries with it being then in inverse sense.

If the calling subscriber has hung up, calling current is sent by thefollowing operation: (Fig. 2) relay 3! moves, being'controlled by a cam,through contact TSI, contact T242 of relay 24, contact b2, wire A (Fig.1), contact T33,'con

tact T22, the bell of the subscriber's station through a condenser,contact T2I of relay 2, line B (Fig. 2), contact C2, resistance,negative battery terminal.

The supervisory lamp flashes, being controlled by a fast moving cam; itscircuit is completed through contact T24! of relay 24.

When the subscriber takes off his receiver, the relay 2'! is closed onthe release of relay 3! (Fig. 2) over a circuit similar to the precedingone, the loop being provided in the subscribers station.

Throughground, contact T2'II of relay 2'! (Fig. 2), contact e2, thecombiner X3 rotates to reach its position 3.

The relay 3' (Fig. 1) returns to rest position, but relay 2' remains inoperated position, being mechanically held, the condenser is againinserted in the line wire A. The continuity of the line wires iscompleted through contacts d3 and 03 (Fig; 2), and the operator may thenspeak to the subscriber.

Through ground and contact :13, relay 23 is energized, and at itscontacts T232 and T235 connects the supervisory relay 25 to the linewires (Fig. 2). Through ground contact (13, the A. C. relay 24 beingshort circuited, opens, relay 3| is interrupted by the cam at contactT242 of relay 24. Supervision is given by relay 25. If the subscriberhangs up, relay 25 is energized over the circuit: (Fig. 1) ground,rectifier, resistance, contact R32, switch hook, contact T2! wire B(Fig. 2), lower winding of relay 25, negative battery terminal. ,az.

The supervisory lamp is lighted over the circuit: ground, through thepilot relay (not shown), contact T252 of relay 25, contact T23! of relay23, contact RZM of relay 24, contact of the jack, lamp, negative batteryterminal. The pilot relay is connected to the two arrow-marked terminalsimmediately above XI in the lower left corner of Fig. 2.

When the operator depresses the key of the dialing device, the ground ofthe auxiliary contact of the jack is connected to the wire I (3 and I-being connected together) and by the contact d3 causes combiner X3 toadvance to its position 4.

The winding of relay 26 is short circuited by the ground on contact a l(Fig. 2).

By release of relay 26, the actuating circuits of the two relays 28 and28 is re-established. Rotary' switch XI comes to rest as well as all theindividual selectors.

Through G the rotary switch also returns to its rest position it it isnot already there.

When relay 25 and rotary switch X2 have returned to their restpositions, the rotary switch combiner X3 rotates to reach its position 5through the circuit: ground, contact T225 of relay 22, contact R265 ofrelay 26, rest contacts of bank XZa, contact ed, and so on. X2a is thebank of rotary switch X2.

In position 5, the ground of wire 5 energizes relay 3| by he and contactR324. At contact R3I I, the negative battery on the wire 2 is removed,which permits the dial lamp to light.

At contact T3II' of relay 3I', the winding of relay 2 I is connected tothe dial switch and follows the dialing impulses (Fig. 2).

The dialing impulses cause rotary switch X2 to advance by virtue of thecircuit: ground, contact T2 of relay 2|, winding of rotary switch X2,negative battery terminal.

If the rotary switch XI has had time to return to rest position, itcommences to rotate again, the

control ground connection onthe' actuating windings of relay'28 andrelay 2c in order t'opassposition-Di) being that given by the bank b ofrctary' switch X2 Relays 23 and 2e are then. controlled by the groundconnection of bank XId..

Impulses are then sent through the line and cause the individualselectors to turn.

When rotary switch XI reache an azimuth corresponding to that whichrotary switch X2 has assumed after reception of the dialing impulses,the relay 26 is closed over the circuit: negative battery terminal,resistance, bank X2a, bank Xia, contact R322 of relay 32, contact C5,lower winding of relay 26.

Relay 25 is held by contact T251 and at contact R262 opens the circuitwhich controls relays 23 and 29, thus limiting the number of impulses tothe number which is registered on rotary switch X2.

The operator then liftsthe dialkey,relays 3I' and 2! open. When thecalling key is depressed, the relay Ed is held by the tip of the plug,wire A, contact (15, contact RSZIS of relay 3i, winding of relay 2 3,wire B, sleeve of the plug, and is held by its lower winding. Rotaryswitch combiner X3 rotates to reach its position 6 by virtue of thecircuit: (Fig. 2) ground, contact T22I, of relay 22, contact T246 ofrelay 24, contact Tree of relay 26, contact c251, and so on.

The relays 2 and 3 (Fig. 1) of the called subscribers station areenergized over the circuit: (Fig. 2) negative battery terminal,resistance, contact 03, wire b (Fig. 1), contact of the sector a,contact R23 of relay 2, windings of relays 2' and 3 in series, rectifierI926, ground, relay 2 connects the subscribers station to the line atcontact T22 of relay 2, and contact T2Ii" and relay 3 short circuit'thecondenser of the wire A.

Relay SI (Fig. 2) moves. controlled by the cam and over the circuit:contact T3II' of relay '3I, contact T25 1 of relay 24, contact 56, wireA, and then ringing current is sent.

The supervisory lamp flashes, controlled by a fast acting cam, itscircuit being closed at contact T24I of relay 24.

When the called subscriber takes off his receiver, relay 2? is held bythe circuit previously referred to, rotary switch combiner X3 rotates toreach its position i, by virtue of the circuit, ground, contact TZ'II ofrelay 21, contact at, and so on.

At Bi and Cl, the continuity of the line wires is completed.

By contact bl, the winding of relay 24 is short circuited and the relayopened.

The winding of relay 23 is energized by contact (1?, and connects thewinding of relay 25 to the line, and prepares the supervisory circuit.

When the operator pulls out the plug, the relay 22 opens and the rotaryswitch combiner X3 rotates to reach its position 8 by virtue of thecircuit: ground, contact R22! of relay 22, contact fl, and so on (Fig.2).

Communication is then established.

If one of the subscribers then hangs up, relay 25 is energized asbefore, and rotary switch combiner X3 reaches its position 9 by virtueof the circuit: ground, contact T233 of relay 23, contact T25I of relay25, contact f8, and so on, and relays 23 and 25 open.

At position 9, the relay 26 is short circuited by contact a9 and opens,and relays 28 and 29 move and cause the return to rest of the individualselectors and of rotary switch XI. Rotary switch X2 returns to restthrough C9.

When rotary switch X! has returned to rest position, the rotary switchcombiner X3 rotates to reach its position I!) by virtue of the circuit:ground, rest contacts of bank Xlc, contact f3, and so on.

Relay 233 which had opened, is again energized by contact alt, androtary switch combiner X3 returns'into position through contact T233 ofrelay 23 (Fig. 2). During the passage through position Hi, negativebattery has been connected to the wire B by contact Cifl and has causedthe energization of the relays 3 (Fig. 1) of the stations over thecircuit: negative battery through wire B, rest contact of sector a,contact T24 of relay 2, winding of relay 3, rectifier i963, ground.

Relay 3 then causes the release of relay 2 (Fig. 1) by unlocking amechanical device, and all the elements are freed.

If the communication desired is not a local communication, the operatorwill pass it, as usual,

' and supervision occurs as before, the rotary switch combiner X3 beingat position 3 (Fig. 2).

On pulling out the plug, relay 22 opens, rotary switch combiner X3rotates to reach its position ii by virtue of the circuit: ground,contact R22! of relay 22, contacts iii to fl, and so on.

Relay 23 is again energized by contact a8, and when the calledsubscriber hangs up, the relay 25 is energized, and rotary switchcombiner X3 rotates to reach its position 9 by virtue of the circuit:ground, contact T233 of relay 23, contact T25! of relay 25, contact f8.7 7

At the position 9, the rotary switch X! the rotary switch X2 return torest position, as well as the individual selectors, as seen above, andat position it, a releasing impulse is sent through the wire B.

When the operator desires to pass a call to a station on the party line,the operator plugs in, after being assured that the circuit of the lampwhich indicates that the line is not busy, is closed, and the operatordepresses the dialing key.

Relay 3| is energized over the circuit: ground, auxiliary contact of thejack, wire 3, then wire I connected by the dialing switch, contact be,contact R32 of relay 32, winding of relay 3!, nega- V ,tive batteryterminal (Fig. 2).

' Relay 3 l on being energized removes the negative battery connectionat contact Rti i of the wire 2, which permits the lighting of the diallamp, while relay 22 is energized over the circuit: ground, auxiliarycontact of the jack, contact T3i2 of relay 3 i winding of relay 22,nega- At contact REizB of relay 22, the circuit of the call lamp isopened.

The dialing of the number has taken place as above explained. It isstopped by the energization of relay ZBover a circuit similar to theprecedin one'which causes the operation of relay 2 by virtue of thecircuit: negative battery terminal, resi tance, contact of relay 26,contact dl, lower winding of relay 2t, ground. The relay Ztis held bycontact T2 i2 of relay 24 (Fig.

Rotary switch combiner "3 then rotates to reach its position 2 by virtueof the circuit; ground, contact "522i. of relay 22, contact T255 ofrelay 24, contact T265 of relay 23, contact 64, and so on; e

and

Relay 3!, having its circuit opened at lil', be; comes deenergized, andthe dial lamp is extinui'shed.

Through contact at, then contact oi, the ringing machine is set intooperation.

Negative battery is connected to wire B through contact G2, which causes(Fig 1) the return to operated condition of relays 2 and 3',as aboveseen, while ringing current is sent through the wire A by virtue of thecircuit: contact T31! of relay 3i, contact TEM of relay 24, contact 02,

relay 3i moving controlied by a cam by contact T245 of relay 24.

The operator observes the return of the:call

through contact T244, condenser, contact T243 The release and the returnto rest position of the various elements then takes place as ex plainedabove. a

Referring to Fig. 3, there will now be conside-red the case Where thecommunication utilizes equipment controlled by a rural automaticexiiiiange. A singl supplementary battery is necessary, its terminalconnected to ground being either the positive terminal or the negativeterminal, according to the particular circumstances. V V a The two wiresshown on the right margin of Fig, 3, are the trunk line extending to aremote automatic exchange or to another remote rural center. In somerural automatic exchanges, the subscribers stations are supplied by alocal battery. The'transmissicn of dialing impulses is efiected by theoperator of the center to which the calling subscriber is connected;

The number transmitted by the operator causes in one or more automaticoffices andrural centers connected in a chain, dinferent selectionspermitting the reaching of the called station.

connected to a rural automatic exchange, which equipment is placed in arural center. On the,

left side of this figure, the line wires A and B are the party linetothe subscribers stations, as

A, B, to an automatic exchange or to another distant rural center. 7 v

In the rural center where there is placed the equipment 'of Fig. 3, anoperator can take the party line by the jack of the line P. i 7

relay 2, rest contact of sector a, wire B (Fig. 3),

contact 120, contact R264 of relay 26, upper winding of relay 38,positive battery terminal. The negative pole of the battery is connectedto ground over the circuit: ground, contact an, rest contacts of bankXlb, and negative battery terminal. Kid is the bank of the rotary switchXi. Relay 3%) is held over the circuit; ground, con- 7 Fig. 3 shows theequipment of a party line,

.cuit: ground,

:tact T335 of relay 33, contact R28! of relay 28,

lower winding of relay 3!], resistance, negative tery terminal of therural central exchange is appliedto the wire A, producing a call to therural automatic exchange (Fig. 3).

When the distributor of the rural center has concluded its operation, anegative battery voltage is applied to the :wire B which causes it toenergize in the negative position the polarized relay 1 (Fig. 3)connected to ground by contact R25! .of relay 25.

Relay 26 is energized through contact TH and negative battery, androtary switch combiner X3 rotates to reach its position I by virtue ofthe circuit: ground, contact T232 of relay 26, contact f0, contactofcombiner X3, winding of cornbiner X3, negative battery terminal.

Then, relay 29 is energized over the circuit: negative battery terminal,resistance, winding of relay 2%), contact R2 32 of relay 23, restcontacts of bank Xl-c, contact T336 of relay 3%, contact T262 of relay2-5, ground (-Fig. 3).

Through contact cl, the supplementary battery has its positive terminalconnected to ground. By contact T233 of relay 29, the negative batteryterminal is connected to wire A.

Relay ,2] is energized through contact T232 of relay 29 and at:itscontact T2 short circuits the relay:2,9 which becomes de-energizedand opens. The impulse of the line Wire A will have freed the individualselectors at the a: position of rest,

.while rotary switch XI advances by one step,

relay 2!! (Fig. 3).

Then relay 2-3 is again energized over the cirbank Xlc, and contact R232of relay 23.

Through bank Xld of rotary switch XI, the negative terminal of thesupplementary battery at the manual central office is connected toground, the next impulse willapply the negative voltage of "thesupplementary battery ,(i. e.

ground) to wire A, while wire 13 will be connected to the positiveterminal of this battery by contact T23] of relay 29 at bank XII) ofrotary switch X I.

The stopping on the calling subscriber will take place by energizationof relay 2.3 over the following circuit:

Positive terminal of the supplementary battery (its negative terminalbeing connected to ground by bank Xid), upper winding of relay 2.8 (Fig..3), contact T332 of relay 35, contact ei, contact R25, wire 13 (Fig.1)., contact of sector a in the azimuth of the station sought, contactT22 of relay 2, resistance I935, rectifier i933, round.

Relay 28 is held by its contact TZBI and interrupts at its contact R282the control of the relays 29 and 21 (Fig. 3)

At contact T283, relay 28 prepares the circuit passing over the positionI of rotary switch combiner X3.

At its contact T284, relay 28 completes the continuity of wire 33.

At its contact R231 relay 28 opens the circuit of relay 38 which becomesLie-energized and opens.

The negative battery voltage on the wire A towards the automaticexchange is out 01f at contact R235 of relay28.

The relays 2' and 3' (Fig. 1) are energized Cover the circuit: negativebattery terminal, con- 10 tact T286 of relay 28, contact R332 of relay3!], contact cl, contact R29! of relay 29, wire B, and so on.

Relay .2 (Fig. l) connects the subscribers station to the line and thuspermits the hearing of the waiting signal which is sent by the ruralexchange on the line wire A if the subscriber has takenoif his receiver,the waiting signal passing by contact (1!, condenser, wire A of theparty line (Fig. 1), T33, T22, the subscribers station, T2l (Fig. 3),T283, condenser, line wire 13: of the party line, toward the ruralexchange.

In the arrangement shown in Fig. 4, for the equipment of eachsubscribers station. in the case in which the call is registered by theengagement of -a member controlled manually, the rectifiers 2233, 4333,4304, 4336, the resistance (i325, and the jacks 4331, 4302, correspondrespectiveyto the elements I903, I933, i334, i336, 1325, mm, I322, ofFig. 1.

When the operator of the rural manual center plugs in, a positivebattery voltage is applied on the wire B which brings the relay I intothe positive position. Relay .26, which is retarded, remains held bycontact Tl l, positive, and contact T253 of relay .26 (Fig. 3).

Through the circuit: ground, contact Tl2 positive, contact T26! of relay.26, contact T283 of relay 2-8, contact fl, and so on, the rotary switchcombiner X3 rotates to reach its position 2.

At contact 012, the condenser of the wire A is short circuited, and bycontact d2 a negative battery voltage is applied tothe wire B toward thesubscribers stations, which causes the relays .2 and 3' of thesubscribers station to be held (Fig. l) as described above, and theringing current is sent by the rural center to the called subscriber.

When the calledsubscriber answers, providing the loop, the negativebattery voltage applied to Wire B by the contact.cl2 through the loop ofthe subscriberis station, energizesthe relay stopping the call of therural center.

The negative battery voltage is .connected to .the wire B, and positivebattery voltage is applied to the wire A.

The polarized relay I thus comes into its negative position which causesthe rotary switch combiner to advance into its position 3 by virtue ofthe circuit: contact T12, negative, contact 2, and so on (Fig. 3),

,At contacts 113 and (13 the continuity of the line wires is completed.

Through contact 03, relay 25 is energized. and at contacts T253 and T255of relay 25, it connects the relay 23 to the party line wires A and Btoward the subscribers stations, while relay 25 also connects thepolarized relay [to the party line wire A at contact T252 of relay 25,contact 123, and the interruption of the ground at contact R25! of relay25.

In case the subscriber hangs up, the relay 23 is energized over thecircuit: (Fig. 1) ground, rectifier, resistance, contact R32 of relay 3,hook switch, contact T2! of relay 2', line wire B (Fig. 3) contact T255of relay 25, lower winding of relay'23, negative battery terminal.

At contact R232 of relay 23, the relay I (Fig. 3) is disconnected fromthe wire A and is connected at contact T232 of relay 23 to ground, theloop thus opened lights the supervisory lamp at the rural center.

Assume that local communication'is to be handled. By depressing the dialkey, the operator 7 i1 sends a negative battery voltage over the line B,relay I comes into the positive position.

Rotary switch combiner X3 rotates to reach its position 4 by virtue ofthe circuit: ground, contact TI2 positive, contact T256 of relay 26,contact T283 of relay 28, contact f3, and so on.

When position 4 is reached, relay 25 has opened and the winding of relay28 is short circuited by d4.

Through contact a4, a negative battery voltage is sent over the wire A,preventing the dial lamp from lighting. The circuit for return to therest position of the rotary switch X2 is closed through: ground, contactb2, bank X20! of rotary switch X2, contact of rotary switch X2,actuating winding of rotary switch X2, negative battery terminal, thenground, contact e2, contact R223 of relay 22, rest contact of bank X21),of rotary switch X2, the contact and actuating winding of rotary switchX2, negative battery terminal, then ground, and bank X21) of rotaryswitch X2 (Fig. 3).

The actuating circuit of relays 2! and 29 being again completed atcontact R282 of relay 28, im-

' pulses are sent toward thesubscribers stations,

thus causing the individual selectors to return to rest position, aswell as rotary switch XI.

For the rotary switch X2, the brushes corresponding to the bank 2) arespaced by 90 with relation to the banks a, c, d.

Thus, on the first, quarter turn, the banks a, c, d, are active, but notthe bank b; on the second quarter turn, the bank b alone is active.

Rotary switch combiner X3 rotates to reach its position 5 by virtue ofthe circuit: ground, contact TI2 positive, contact T26! of relay 26,contact R253, rest contact of bank X20 of rotary switch X2, contact f4,and so on. X20 is the bank c of rotary switch X2.

Relay 22 has its winding energized over the circuit; ground, contact TI2positive, contact T26! of relay 26, contact b5, rest contact of bank X2aof rotary switch X2, lower winding of relay 22, negative batteryterminal. The application of negative battery voltage is interruptedfrom wire A at contact T22! of relay 22, the operator's dial lamp isthen lighted indicating that the circuit is ready to receive the dialingimpulses. Relay 2| has its winding connected to the wire A by virtue ofthe circuit: (Fig. 3) ground, winding of relay 2!, contact T22! ofrelay'22, contact R285 of relay '28. contact a5, wire A, and thenfollows the dialing impulses. At the first impulse, it is energized by ane ative battery voltage applied to the wire A. Relay 22 is held duringthe dialing impulses by virtue of the circuit: ne ative batteryterminal, resistance, contact T224 of relay 22, the upper winding ofrelay 22, ground. Rotary switch X2 then advances by virtue of theconnection to ground and contact T2II of relay 2|.

If rotary switch X! has rotated to reach its rest position, it thenleaves its rest position, and relays 2'! and 29 are controlled over thecircuit: ground, contact T252 of relay 26, bank X2c of rotary switch X2,rest contacts of bank Xlc of rotary switch XI, contact R282 of relay 28,and so on. The ground control is that of bank Xlc of rotary switch XI(Fig. 3).

Impulses are then sent toward the subscribers stations as has beendescribed above.

At the end of the train of impulses, the relay 2! becomes de-energizedand opens, the winding 1 of relay 22 is short circuited at contact RZIIof.

relay '2! and also opens.

When rotary switch XI has rotated to; reach the azimuth corresponding tothe number which has been dialed and sent, the winding of relay 28 isenergized over the circuit: ground, lower winding of relay 28, contactd5, contact R304 of relay 30, bank Xla of rotary switch XI, bank X2a ofrotary switch X2, resistance, negative battery terminal. r

The control of relay 2? and of relay 29 is removed at contact R282 ofrelay 28, and relay 28 is held by its contact T28l.

Rotary switch combiner X3 rotates toreach its position 5 by virtue ofthe circuit: ground, contact TI2 negative, contact T26! of relay 26,contact T283 of relay 28, contact f5, and so on (Fig. 3). I 7

After having dialed, the operatorlifts the dial key and depresses thecalling key, the effect of which is to send a positive battery impulseover the wire; BI thus remains in positive position, and alternatingcurrent over the wire A is sent by the automatic exchange.

On the other hand, the connection to the line of the called station iseffected by putting a negative battery voltage on the wire B by contact(26.

By contact as (shown at the top of Fig.3 in the sixth vertical columnfrom the left), the condenser of the wire A is short circuited. Thestopping of the calling, on answering, is madein the same manner asabove explained.

The relay I moves into negative position, a negative battery voltagebeing applied on the wire B through therural center, as well as a groundon wine A. The ground placed by the rural center on'the line wire Apermits in position 1 of the rotary switch X3 for relay I to remain inshunt on the line until the operator unplugs.

Rotary switch combiner X3 rotates to reach it position 7 by virtue ofthe circuit: ground, contact TI2 negative, contact f6, and so on.

At contacts a! and til, the continuity of the talking circuit iscompleted.

Through contact 0! of the combiner, the winding'of relay25 is energizedand the winding of relay 23 is connected to the wires A and B atcontacts T253 and T255 of relay 25 (Fig. 3).

Through contact T252 of relay 25, contact b1, the winding of relay I isconnected to the wire A, while at contact T25! of relay 25, it is cutoff from the local ground (Fig. 3)

Supervision takes place in a manner similar to that previouslydescribed.

When a local communication is being handled, the operator pulls out theplug, then relay 26 opens, and rotary switch combiner X3 rotates toreach its position 8 by virtue of the circuit: ground, contact R262 ofrelay 26, contact g1, and so on.

Through contact C3, the relay 25 remains energized, holding the relay 23on the line.

Through contact a8,'relay I is connected to ground, thus permitting itsenergization by the circuit from the automatic exchange.

Local communication is thus established.

If the operator wishes to pass another call, the relay I comes in apositive position, the relay 22 is energized over the circuit: ground,contact TI2 positive, contact R26! of relay 26, winding of relay 22,negative battery terminal.

Through contact T222 of relay 22, contact R255 of relay 26, a negativebattery voltage is applied to the wire A and signals to the operatorwhen the line is busy (Fig. 3).

If a subscriber hangs up his receiver, the relay 23 is energized asbefore, and rotary switch coma-scopes ibiner X3 rotates to reach itsposition 9 by virtue of the circuit: ground, contact T254 of relay 35,contact T23! of relay 23, contact ]3, and so on.

If the local call is interrupted by a timin or 'chronometric relay, thetriple negative :connec 'tion is established. This :chronometric relaycpcrates over the circuit: ground, contact T256 of "relay 25, contactT25! of relay 25, Contact contact of the chronometric relay, winding,nega tive battery. When the contact of the chrono- If the operation issuch that the local call is notzto be interrupted at the endof adefinite time,

the triple positive connection is made.

When the operator located at the test table of the rural center wishesto interrupt the call, the s operator moves relay I into negativeposition and then :into positive position. Relay 26 is thenenergized-and is held, the chronometric relay is put intocircuitthrough: ground, contact Ti-2 positive,

contact T26! of relay 26, contact 298, contact and windingoi the.chronometric relay, negative battery.

When the operator has closed the working contact, the rotary switchcombiner X3 reaches :position 9, and the call is interrupted.

At this position -9, the winding of relay 28 is short circuited by thecontact all), and in opening, the'relay '28 re-establishes a circuit ofthe relays '21 and 29 which move, and cause rotary switch Xi and theindividual selectors to wine to rest.

Through contact 129, bank XZd, the rotary switch X2 comes to rest.

When rotary switch XI has rotated to reach the rest position, the rotaryswitch combiner X3 rotates to reach its position It by virtue of thecircuit: ground, rest contacts of bank Xlb of rotary switch XI, contactf9, and soon (Fig. 3).

In the position I 0, a negative battery voltage is sent over the wire Btowards the subscribers stations by contact dill, and thus produces, asabove described, the release of the members belonging to thesubscribersstations.

Through contact c'HJ, the winding of relay 25 is energized, and byvi-rtueof the circuit: ground, contactT254 of relay 25, contact fI-ll,and so on, causes rotaryswitch combiner Xi? toadvance to its positionEl. All the parts are then freed.

If the call requested is not a local call, the op erator passes it inusual manner, and the supervision operates as has been described above,the rotary .switch combiner 7X3: zbein'g stopped at its position 3.

When the plug is pulled out, the :relay l and the relay 26 arede-energized and opened, and the rotary switch combiner X3 rotates toreach its position 8 by Virtue of the circuit: ground, contact R262 ofrelay 26, contacts 93 to Q1, and

ISO .011.

At position 8, thewwinding of relay 25.115 energizedand the position 8is freed over the circuit: ground, contact T254 of relay 2.5, contactT23! of relay 23, contact f8, the winding of relay 23 being energizedwhen a subscriber has hung up his receiver.

Upon reaching position 9, the rotary switches come to rest in the samemanner as has been above described, and upon reaching position Iii,release takes place.

If the operator desires to pass a call to a subscribers station on theparty line, the operator plugs in, and on depressing the dialing key,sends a positive battery impulse. over the line 'B, the

:effect of which is to cause relay to come into the positive position.Relay 2.6 is energized over the circuit: ground, contact TH positive,contact be, winding of relay 26, negative battery (Fig. 3)

'Rotary switch combiner X3 rotates to reach its position .I by virtue ofthe circuit: ground,

contact T2132 of relay 2.5,.ccntact f0, and so on.

At this position I, the winding of relay 22 is energized over the.circuit: ground, contact Tit positive, contact 'l2tl of relay 26,contact bi, rest contacts of bank X2a of rotary switch X2, lower Pwinding .of relay 22, negative battery, and at contact R22! .of relay 22interrupts the negative battery connectionoi wire A.

Through contacts of relay '22 and R235 of relay 23, contact a], thewinding of relay 2| is connected to .the wireA and follows the dialingimpulses. These dialing impulses are produced as above explained.

The sending of the dialing impulses to the stations, and the stopping,are effected as before described. The winding of relay is then energizedthrough contact all. The succession of operating steps is identical withthat above described.

If the tester wishes to make tests, the tester calls a subscriber asabove, and then the rotary switch ccrnbiner'iiii havin arriv-edat itsposition 5, the tester dials the number 3.1 on dial, which causes rotaryswitch X2 to advance to the position of rest of sector 12 shiftedthrough 90' with respect to the others. Relay 22 becomes ale-energizedand opens at the end of the train of dialing impulses.

To describe the operation in more detail, the

rotary switch combiner X3 rotates to reach its position 3 by virtue ofthe circuit: ground, T12 positive, contact T26! of reiay '26, contactT263 of relay 25, contact it}, and so on.

Upon reaching position 1, the winding of relay 28 is short circuitedthrough ground, and contact d4, and releases. Relay 22 returns to restposition at the end of the train of dialing impulses.

Rotary switch X2 returns to rest position by virtue of thecircuit:ground, contact be, bank (i, then ground contact 041, contact R223 ofrelay 22, on the contact be, then ground and bank b.

Rotary switch combiner X3 rotates to reach its position 5 by virtue ofthe circuit: ground, contact TIZ positive, contact T25! of relay 26,contact R283 of relay contact Co of rotary switch X4, contact it, and soon.

The winding of relay 24 is energized over the circuit: ground, windingof relay 2 contact 05, contact R223 of relay 22, rest contacts of bankX2?) of rotary switch X2, contact and winding of rotary switch X2,negative battery terminal (Fig.3).

Upon being energized, relay 24 holds relay 25 through its contact butopens l or" wire B at contact R2 33 of relay vZ ta-rid at contacts Ti ilSid Ti'itt of relay 2 it maintains the metallic continuity of the linewires.

The chronometric relay set in operation by contact T2 i i of relay 24permits of making tests, during the time that it takes to close itsworking contact. When the working contact is established, the rotaryswitch combiner X3 rotates to reach its position ii by virtue of thecircuit: ground, contact TZM of relay 24, contact of the chronometricrelay, contact T245 of relay 24, contact 95, and so on.

15 The energizing circuit of relay 24 is interrupted at contact c5, andrelay 24 becomes de-energized and opens, being followed by relay 26.

Rotary switch combiner X3 rotates to reach its position 8 by virtue ofthe circuit: ground, contact R262 of relay 26, contacts at and g7, and

so on (Fig.3).

When the subscriber hangs up his receiver, the position 8 is passed, therelay 25 is energized, and the receiver having been hung up, relay 23 isoperated over the circuit: ground, contact T254 of relay 25, contactT23! of relay 23, contact f8, and so on.

At position 9, the rotary switch X2 passes the position of rest ofthesector bZJi (as shown in the lower right corner of Fig. 3) over thecircuit: ground, contact e9, contact R223 of relay 22, rest contacts ofbank X21) of rotary switch X2,-contact and winding of rotary switch X2,

negative battery. Rotary switch X2 returns to its rest position throughthe sector 12.

The position 9 is passed by: ground, rest contacts of bank Xlb of rotaryswitchXl, contact f9, and so on.

The sending of the negative wire impulse over the wire B producing therelease of the subscribers station and the passage from the positionit], takes place as has been above described.

The embodiments which have been above described, have been given by wayof example, and certain parts described, or groups of parts, could bereplaced by other elements giving the same result, or all such elementsor parts of them could be combined with difierent embodiments withoutdeparting from the scope of the present 7 invention.

It will be apparent to those skilled in the art that my invention issusceptible of modifications to adapt the same to particular operatingconditions, and all such modifications which are within the scope of theappended claims I consider to be comprehended within the spirit of myinvention. 1

I claim:

1. In a party line telephone system: a central exchange; a subscribersstation; a line comprising a first and a second wire for connecting saidexchange to said station; in said station: a switch comprising anactuating electro-magnet, a first and a second row of contact studs, afirst brush and a second brush capable of simultanecusly hunting oversaid two rows respectively, each of said two rows comprising a homingposition, the homing position of said second row being grounded and theother contact studs of said second row being strapped; a connectionbetween said first brush and said second wire; a connection between saidsecond brush and said first wire through the winding of saidelectromagnet and a rectifying cell; a connection between the homingcontact stud of said first row of contact studs and a ground through arectifying cell and a make contact; means for closing said contact andholding it in closed position; in said central exchange: a startingrelay whose winding is connected at one end to said second wire and atits other end to a battery terminal and means operated by said startingrelay for applying the other battery terminal to said first wire; bothcells being so oriented as to allow the passage of current therethrough.

2. A party line telephone system according to claim 1 in which saidsubscribers station comprises: a connection between one contact stud ofsaid first row of terminals and a ground through a resistance, arectifying cell and a contact which is closed at the same time as saidfirst mentioned contact; a connection relay, one of the two members of aback contact of said connection relay mounted in said connection, aconnection between the other member 'of said back contact and a groundthrough the winding of said connection relay and a rectifyingrcell; saidcentral exchange comprises battery-reversing means; said two rectifyingcells'being'so oriented as to allow the passage of current therethroughafter said battery-reversing means have been operated.

3. A party line telephone system according to claim 2, in which saidconnection relay comprises contacts for connecting said two wires to thesubscribers receiver when said contacts are in front position.

4. A party line telephone system according to claim 2, in which theoperation of said connection relay causes the opening of said contactfirst mentioned in claim 1.'

5. In a party line telephone system: a central exchange; a subscribersstation; a line comprising a first and a second wire for connecting saidexchange to said station; in said station: a switch comprising anactuating electro-magnet, a first and a second row of contact studs, afirst brush and a second brush capable of simultaneously hunting oversaid two rows respectively, each of said two rows comprising ahomingposition, the homing position of said second rowbeing grounded,and the other contact studs of said second row being strapped; a;connection between said first brush and said second wire; a connectionbetween said second brush and said first wire through the. winding ofsaid electro-magnet and a rectifying cell; a connection between acontact stud or" said first row and a ground through a connection relay,2. back contact of said relay and a rectifying cell, said connectionrelay comprising two contacts for connecting said two wires to thesubscribers receiver when said two contacts are in front position andsaid rectifying cell being so oriented as to allow the passage ofcurrent therethrough.

HENRI LOUIS LESIGNE.

REFERENGES CITED The following references are of record in the file ofthis patent: V

UNITED STATES PATENTS Number Name Date 984,204 Erickson Feb. 14, 19111,000,077 Cummings et a1. Aug. 8, 1911 1,067,274 Richey July 15, 19131,206,761 Hastings Nov. 28, 1916 1,457,338 Burrows et a1. June 5, 19231,896,315 Kapp Feb. 7, 1933 2,013,354 Lomax Sept. 3, 1935 Certificate ofCorrection Patent No. 2,540,896 February 6, 1951 HENRI LOUIS LESIGNE Itis hereby certified that error appears in the above numbered patentrequiring correction as follows:

In the grant, line 14, strike out or SEVENTEEN YEARS; same line, afterGRANT insert until July 1, 1.962; and in the heading to the printedspecification, between line 7 and line 8, insert the following: Section1, Public Law 690, August 8, 1946. Patent ewpires July 1, 1.962;

and that the said Letters Patent should be read as corrected above, sothat the same may conform to the record of the case in the PatentOffice.

This certificate supersedes Certificate of Correction issued June 26,1951. Signed and sealed this 11th day of September, A. D. 1951.

[SEAL] THOMAS F. MURPHY,

Assistant Commissioner of Patents.

